This invention relates to facsimile transmitters and receivers of the type utilized to transmit and receive information-bearing signals representing the dark/light variations on a document located at the transmitter and converting the information-bearing signals to marks or images on a copy medium located at the receiver so as to form a copy which is a reasonable facsimile of the original document.
Most facsimile transmitters and receivers in commercial use at the present time are supplied with document or copy medium sheets by hand. In other words, an operator takes an individual sheet of paper, whether the original document or a blank piece of copy medium, and places that sheet on or in the scanning means of the transmitter or receiver, typically a drum having a clamp for clamping one edge of the sheet.
In some commercially available facsimile equipment, cassettes or magazines are utilized to store into the plurality of sheets prior to feeding to the scanning means. These cassettes include separating members which are inserted between adjacent pairs of sheets so as to assure that each sheet will, with reliability, depart the cassettee or magazine at the appropriate time, i.e., there will be no sticking between the sheets resulting in improper feeding of the sheets to the scanning means. In other commercial facsimile equipment, roll feeders are utilized for the copy medium so as to assure the supply of a fresh copy medium to the scanning means with substantial reliability.
As a general rule, it is difficult to sheet feed, automatically or unattended, a paper of any kind with a high degree of reliability. Paper feeding mechanisms are almost by nature prone to paper jams which result when more than one sheet is feed along a predetermined transport path at any one time. In facsimile application, the problem of reliable sheet feeding becomes even more severe because of the common use of electrosensitive paper in facsimile application. Electrosensitive paper which includes a plurality of layers is characterized by a writing surface which is rather glossy in appearance, and for paper feeding purpose, may be considered almost sticky. Great difficulties inhere in trying to sheet feed a stack of such paper without the use of the above-discussed paper separator cassettes or magazines. Yet, a reliable sheet feeder for a stack of such paper is, in general, preferred to the roll-type feeder previously discussed because of operator convenience.